From Rings to Worlds: Linking Terrestrial and Super-Earth Planet Formation

Understanding the formation of rocky planets within our solar system and the abundant rocky super-Earths observed throughout the Galaxy represents one of the most compelling challenges in planetary science. In contrast with the relatively low mass and dynamically dispersed terrestrial planets of the solar system, extrasolar planetary systems frequently host rocky super-Earths — planets several times more massive than Earth — arranged in compact orbital configurations. In this talk, we will discuss a unified theoretical framework linking these phenomena: building upon recent advances that show rapid, localized formation of planetesimals within protoplanetary disks, we propose that rocky planets — both terrestrial and super-Earth class — emerge from discrete, silicate-rich rings located around ~1 au. Our model demonstrates that these planetary bodies predominantly grow through pairwise collisions among planetesimals, reaching characteristic final masses set by isolation and orbital migration processes. Numerical simulations reveal that this framework naturally explains both the characteristics of our solar system’s terrestrial planets and the compact architectures commonly observed in short-period exoplanetary systems, highlighting a fundamental link in rocky planet formation across different planetary environments.